TV Violence Exposure Linked to Cognitive Abnormalities

Posted on June 25, 2014 at 11:44 am

New research has found that young adult men who watch more violence on television showed indications of less mature brain development and poorer executive functioning.[1] For the investigation, Indiana University School of Medicine used psychological testing and MRI scans to measure mental abilities and volume of brain regions in 65 healthy males with normal IQ who were between the ages of 18 and 29.1 According to lead author Tom A. Hummer, PhD, the young men provided estimates of their television viewing over the past year and then kept a detailed diary of the viewing for a week.1

Executive function is the ability to formulate plans, make decisions, reason and problem-solve, regulate attention, and inhibit behavior to achieve goals.1 The participants also completed a series of psychological tests that measured their inhibitory control, attention, and memory.1 MRI scans were used to measure brain structure.1

“We found that the move violent TV viewing a participant reported, the worse they performed on tasks of attention and cognitive control,” said Hummer. “On the other hand, the overall amount of TV watched was not related to performance on any executive function tests. The worry is that more impulsivity does not mix well with the behaviors modeled in violent programming.”1

Hummer continued, “When we looked at the brain scans of young men with higher violent television exposure, there was less volume of white matter connecting the frontal and parietal lobes, which can be a sign of less maturity in brain development.”1

White matter is tissue in the brain that insulates nerve fibers connecting different brain regions, making executive functioning more efficient.1 In typical development, the amount or volume of white matter increases as the brain continues to make more connections until about age 30, improving communication between brain regions.1 Connections between frontal and parietal lobes are especially important for executive functioning.1

“The take-home message from this study is the finding of a relationship between how much violent television we watch and important aspects of brain functioning like controlled attention and inhibition,” said Hummer. “With this study, we could not isolate whether people with poor executive function are drawn to programs with more violence or if the content of the TV viewing is responsible for affecting the brain’s development over time. Additional longitudinal work is necessary to resolve whether individuals with poor executive function and slower white matter growth are more drawn to violent programming or if exposure to media violence modifies development of cognitive control.”1